Embodiments of the invention generally relate to apparatus and methods for depositing a film on a substrate surface and treating the film with UV radiation. In particular, embodiments of the invention are directed to apparatus and methods incorporating a window through which UV radiation can be directed toward the substrate surface while minimizing deposition on the window.
Metal films (e.g., ruthenium) can be deposited by cyclical deposition processes. For example, a substrate can be exposed to a ruthenium organometallic precursor which adsorbs to the surface of the substrate. The organometallic bonds can be broken to drive off the organic portion, leaving a metal film on the substrate surface. The organometallic complex can be decomposed or reduced to the bare metal by, for example, exposure to ultraviolet light. However, the films generally have a significant amount of organic contaminants, resulting in a poor quality metal film.
Additionally, apparatus for this process use a window to separate the reaction space of the processing chamber from the light source. This window can be coated with contaminants, reducing the transparency of the window and decreasing the efficiency of the process. The window may need to be frequently cleaned or replaced, resulting in significant downtime and expose.
Therefore, there is a need in the art for methods and apparatus capable of depositing good quality metal films using light exposure while minimizing downtime associated with cleaning and/or replacement of the window which isolates the light source from the reaction space.